Abstract Tuna farming off Port Lincoln, Australia, involves catching wild 2–4-year-old southern bluefin tuna in summer and then fattening for periods of 2–8 months. As fresh product is not available year-round, the feasibility of maintaining tuna for longer periods was trialled, including over a summer season, when temperatures may exceed 24 8C. As the rates of growth and reproduction in ectoparasites of fishes are usually most rapid during warm temperatures, parasite epizootics at this time may adversely affect the health of tuna.We collected epidemiological data on burdens of metazoans on the gills of tuna from the time of stocking in April 2005 through to final harvest in August 2006 (N = 220).We document an epizootic of the copepod Pseudocycnus appendiculatus, characterised by a significant increase in both prevalence and mean intensity in the first winter, followed by a decline in these parameters over the next 12 months. This epizootic pattern appears to be independent of seasonal changes in temperature. For two other species, a second copepod (Euryphorus brachypterus) and a polyopisthocotylean flatworm (Hexostoma thynni), there were no clearly discernible trends in infections. As the high water temperatures over the summer period did not lead to increased infections of any species of gill parasites, we conclude that they do not threaten the feasibility of farming of Thunnus maccoyii. # 2008 Elsevier B.V. All rights reserved. Keywords: Aquaculture; Epizootic; Epidemiology; Monogenea; Parasitic copepoda

Item Type:	Refereed Article
Research Division:	Agricultural and Veterinary Sciences
Research Group:	Fisheries Sciences
Research Field:	Fish Pests and Diseases
Objective Division:	Animal Production and Animal Primary Products
Objective Group:	Fisheries - Aquaculture
Objective Field:	Aquaculture Tuna
UTAS Author:	Hayward, CJ (Dr Craig Hayward)
UTAS Author:	Aiken, H (Mr Hamish Aiken)
UTAS Author:	Nowak, BF (Professor Barbara Nowak)
ID Code:	56538
Year Published:	2008
Web of Science® Times Cited:	12
Deposited By:	NC Marine Conservation and Resource Sustainability
Deposited On:	2009-05-11
Last Modified:	2014-11-25
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